A146214 a(n) = (10^n)-th lower twin prime.

3, 107, 3821, 79559, 1260989, 18409199, 252427601, 3285916169, 41375648687, 507575862527, 6100479510551

Offset: 0

Author

Cino Hilliard, Oct 28 2008

Keywords

• nonn
• more

Comments

The Gcc with Gmp program is at the bottom of the link. The link also has a PARI bisection algorithm which gives a very good approximation for the n-th prime number and the n-th twin prime number. For example the 10^10-th lower twin prime approximation is 6100475249386, this has a relative error of 0.000000698... from the actual a(10) above.

The (10^n)-th upper twin prime is given as a(n)+2 = (5,109,3823,79561, 1260991,18409201,252427603,...). - M. F. Hasler, Dec 06 2008

Examples

			For n=1, the first 10 lower twin primes (A001359) are: 3,5,11,17,29,41,59,71,101,107. So a(1) = 107 is the 10th lower twin prime.
		

Links

• Cino Hilliard, Approximating the n-th lower twin prime (broken link)

Crossrefs

Cf. A001097, A001359, A147797.

Formula

a(n) = A001359(10^n). - M. F. Hasler, Dec 06 2008

Extensions

a(0) from Zak Seidov, Oct 29 2008

Edited and cross-references added by M. F. Hasler, Dec 06 2008